Many applications call for the sensing of pressure at a plurality of locations. By way of example in the vehicular environment, electro-hydraulic brake systems often have a plurality of different locations that sense fluid pressure. For example, pressure sensing at each wheel for closed loop brake force control, at a location to sense driver input and, if desired, at a pressure accumulator to sense systems reserve pressure. Hydraulic sensing points are all routed through the hydraulic/electrical control unit or HECU having a system controller, i.e., microprocessor, to process the inputs provided by the different hydraulic circuit pressures. The provision of discrete pressure sensors with full conditioning electronics results in suitable operation, however, it also results in a relatively high total pressure sensor cost as well as significant spatial requirements.
In co-assigned U.S. Pat. No. 6,687,642 which issued Feb. 3, 2004, and copending application Ser. No. 10/743,363 filed Dec. 22, 2003, condition responsive systems are described and claimed in which the outputs of a plurality of condition responsive sense elements are processed by an electronic circuit and provided to an external system controller for use in a HECU system.